This is an attempt to reverse-engineer an open source and modernized engine for the game. There are already builds for people to install and evaluate. As of May/2017 what's done: Loading a level with all models, textures, monsters, level changes; The core of the game process - you can run, jump, shoot; Primitive AI of monsters; Partially implemented level scripts - any moving walls, switches, etc.; Some sound effects; Tearing off the limbs; Ability to play online games. Individual network modes will be later; Save / Load. What remains to be done: Completion of monster's AI; Completion of the network game; Completion of collisions with map objects; PowerUps; Fix a thousand and one bugs; There are many more things.